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Uncommon star 22 EP

HR 2458

RA 100.3218° · Dec 11.0032° · star

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Score breakdown

· 4 badges
22 pts · Uncommon
Uncommon 34 pts → Rare
  • Deep red star +8
  • Giant star +6
  • Cool red M-type star +5
  • Star +3
Total score 22

12 more points to reach Rare.

Badges

  • Star · +3
  • Cool red M-type star · +5
  • Giant star · +6
  • Deep red star · +8

Trivia

What it actually is

  • Spectral class. Its spectrum reads M1III — an M-type red star — and M stars are the silent majority: roughly three of every four stars in the galaxy are one.
  • Where it is in life. It is a giant. It has already exhausted its core hydrogen and swollen up enormously in response.

Find it in the sky

  • How to spot it. At magnitude 6.2 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Monoceros.
  • Northern sky. It rides the northern half of the sky — an easier target the further north you are.
  • Best time of year. It stands highest in the middle of the night around December — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out deep orange-red (B−V 1.7) — one of the coolest surfaces a star can have while still fusing.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 3550 K, against the Sun's 5778 K.

What's in a name

  • Its catalogue. The HR number is from the Bright Star Catalogue — roughly 9,100 stars, essentially everything the unaided eye can see.

Properties

absmag
-13.81
bv
1.675
constellation
Mon
luminosity
29107171.1807
mag
6.19
name
HR 2458
spect
M1III

About HR 2458

HR 2458 is an uncommon star. It sits in the constellation Mon, shines at apparent magnitude 6.19 and has spectral type M1III.

Its spectrum reads M1III — an M-type red star — and M stars are the silent majority: roughly three of every four stars in the galaxy are one.

How to see it

Look for HR 2458 in the constellation Mon. At apparent magnitude 6.19, it is an easy target for binoculars.

Like any astronomical target, HR 2458 is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.

Why HR 2458 is an uncommon star

HR 2458 scores 22 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 12 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, Cool red M-type star, Giant star and Deep red star — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.